Abstract

The cell loss priority (CLP) bit in the header of the ATM cell may be used either by the network to tag noncompliant cells, or by the application to declare two levels of quality-of-service (QoS) within the same virtual circuit (VC). We study the possibility of the use of this bit by the application alone. An application can offer two types of traffic streams to the network, namely, a precious traffic stream (with stringent QoS requirements, e.g., cell loss ratio (CLR) < ${10}^{-9}$ and identified by the CLP bit=0) and a less precious stream (CLP = 1 and less stringent QoS requirements, e.g., CLR < ${10}^{-4}$). We study the performance of an ATM multiplexer with two traffic classes with different QoS requirements. The buffer priority schemes adopted are partial buffer sharing (PBS) and PBS + push-out (PO). We first obtain the engineering trade-off curves, between CLP = 0 and CLP = 1 traffic. To identify an operating point, we formulate a revenue optimization problem in which the constraints are the engineering trade-off curve and a simple model of the variation of CLP = 1 demand with its price.